Elevated Blood Lead Levels and Reading Readiness at the Start of Kindergarten

Abstract

WHAT'S KNOWN ON THIS SUBJECT: Blood lead levels well below 10 mg/dL are now recognized as causing adverse cognitive effects, including lower scores on standardized reading and math tests. WHAT THIS STUDY ADDS:This is the first study to show that reading readiness early in kindergarten is independently associated with blood lead levels well below 10 mg/dL. Results suggest that lead exposure may have a larger impact on urban education than national estimates suggest. abstract OBJECTIVE: To evaluate the relationship between blood lead levels (BLLs) and reading readiness at kindergarten entry, an early marker of school performance, in a diverse urban school population. METHODS:Kindergarten reading readiness test scores for children attending public kindergarten in Providence, Rhode Island, were linked to state health department records of blood lead testing by using individual identifiers. The study population (N = 3406) was 59% Hispanic. For each child, the geometric mean BLL was estimated by using all previously reported BLLs. Analyses were adjusted for gender, age, year enrolled, race, child language, and free/reduced lunch status as a measure of socioeconomic status. RESULTS:The median geometric mean BLL was 4.2 mg/dL; 20% of children had at least 1 venous BLL $10 mg/dL. Compared with children with BLLs ,5 mg/dL, the adjusted prevalence ratios (95% confidence interval [CI]) for failing to achieve the national benchmark for reading readiness were 1.21 (1.19 to 1.23) and 1.56 (1.51 to 1.60) for children with BLLs of 5 to 9 and $10 mg/dL, respectively. On average, reading readiness scores decreased by 4.5 (95% CI: 22.9 to 26.2) and 10.0 (95% CI: 27.0 to 213.3) points for children with BLLs of 5 to 9 and $10 mg/dL, respectively, compared with BLLs ,5 mg/dL. CONCLUSIONS: BLLs well below 10 mg/dL were associated with lower reading readiness at kindergarten entry.

High prevalence of elevated blood lead levels in both rural and urban Iowa newborns: Spatial patterns and area-level covariates

“…The literature examining lead exposure or poisoning in childhood focuses predominantly on urban communities [26, 32, 35–49]. Few studies examine rural inhabitants, particularly rural children, and those that do often find lower lead exposure or lower blood lead levels in rural versus urban populations [24, 50–58].…”

Lead Exposure and Behavior: Effects on Antisocial and Risky Behavior Among Children and Adolescents

“…Investigating IQ and cognitive impairment, Ferrie, Rolf, and Troesken (2012) link lead in water to lower intelligence test scores for American army enlistees during World War II; Rau, Reyes, and Urzua (2012) study effects on academic performance in Chile; Nilsson (2009) studies the cognitive and labor market effects of the removal of lead from gasoline in Sweden; and McLaine et al (2013) and Reyes (2015) show effects on school test scores in Rhode Island and Massachusetts, respectively. Investigating IQ and cognitive impairment, Ferrie, Rolf, and Troesken (2012) link lead in water to lower intelligence test scores for American army enlistees during World War II; Rau, Reyes, and Urzua (2012) study effects on academic performance in Chile; Nilsson (2009) studies the cognitive and labor market effects of the removal of lead from gasoline in Sweden; and McLaine et al (2013) and Reyes (2015) show effects on school test scores in Rhode Island and Massachusetts, respectively.…”

A review of environmental lead exposure and management in Mount Isa, Queensland

“…Lower IQ scores are considered to increase poverty rates, incarceration rates, high-school dropout rates, and the number of welfare recipients (7). Prenatal and childhood lead exposure has been shown to be associated with higher rates of criminal behaviour and reduced preparedness for kindergarten (8). Notwithstanding the social cost, the economic cost of widespread neurodevelopmental deficits related to lead is estimated to be in the order of billions of dollars (9).…”